Microfluidic flow cells that are used in, for example, microarray chemical analysis typically have small holes for fluid inlet and outlet. When the microarray area covers a large area, such as in high throughput analysis, the flow becomes localized between the fluid inlet and outlet, which results in high non-uniformity of the analyte across the surface of the microarray. To help alleviate this problem, a higher flow rate for the analyte fluid may be used to exchange the fluid in the flow cell; however, such high flow rates are undesirable because the analyte is often precious and may be present at low concentration.